Traumatic brain injuries (TBIs) constitute a significant public health issue and a major source of disability and death in the United States and worldwide. TBIs are strongly associated with high morbidity and mortality rates, resulting in a host of negative health outcomes and long-term complications and placing a heavy financial burden on healthcare systems. One promising avenue for the prevention and treatment of brain injuries is the design of TBI-specific supplementation and dietary protocols centred around nutraceuticals and biochemical compounds whose mechanisms of action have been shown to interfere with, and potentially alleviate, some of the neurophysiological processes triggered by TBI. For example, evidence suggests that creatine monohydrate and omega-3 fatty acids (DHA and EPA) help decrease inflammation, reduce neural damage and maintain adequate energy supply to the brain following injury. Similarly, melatonin supplementation may improve some of the sleep disturbances often experienced post-TBI. The scope of this narrative review is to summarise the available literature on the neuroprotective effects of selected nutrients in the context of TBI-related outcomes and provide an evidence-based overview of supplementation and dietary protocols that may be considered in individuals affected by—or at high risk for—concussion and more severe head traumas. Prophylactic and/or therapeutic compounds under investigation include creatine monohydrate, omega-3 fatty acids, BCAAs, riboflavin, choline, magnesium, berry anthocyanins, Boswellia serrata, enzogenol, N-Acetylcysteine and melatonin. Results from this analysis are also placed in the context of assessing and addressing important health-related and physiological parameters in the peri-impact period such as premorbid nutrient and metabolic health status, blood glucose regulation and thermoregulation following injury, caffeine consumption and sleep behaviours. As clinical evidence in this research field is rapidly emerging, a comprehensive approach including appropriate nutritional interventions has the potential to mitigate some of the physical, neurological, and emotional damage inflicted by TBIs, promote timely and effective recovery, and inform policymakers in the development of prevention strategies.

Mounting evidence indicates a close correspondence between episodic memory, mental imagery, and oculomotor behaviour. It remains unclear, however, how oculomotor variables support endogenously driven forms of mental imagery and how this relationship changes across the adult lifespan. In this study we investigated age-related changes in oculomotor signatures during scene construction and explored how task complexity impacts these processes. Younger and cognitively healthy older participants completed a guided scene construction paradigm where scene complexity was manipulated according to the number of elements to be sequentially integrated. We recorded participants' eye movements and collected subjective ratings regarding their phenomenological experience. Overall, older adults rated their constructions as more vivid and more spatially integrated, while also generating more fixations and saccades relative to the younger group, specifically on control trials. Analyses of participants' total scan paths revealed that, in the early stages of scene construction, oculomotor behaviour changed as a function of task complexity within each group. Following the introduction of a second stimulus, older but not younger adults showed a significant decrease in the production of eye movements. Whether this shift in oculomotor behaviour serves a compensatory function to bolster task performance represents an important question for future research.

This study is the first to investigate interactions between hormonal contraception and the gut microbiota in a cohort of physically active young females across the menstrual cycle. Our findings suggest that hormonal contraception may influence gut microbiota composition, potentially through a reduced relative abundance of short-chain fatty acid-producing taxa. Experimental studies are needed to confirm these associations and explore their potential implications for metabolism, health, and performance.

Humans spend approximately one third of their life asleep but, as counterintuitive as it may sound, sleep is far from being a quiet state of inactivity. Sleep provides the opportunity to perform numerous biological and physiological functions that are essential to health and wellbeing, including memory consolidation, physical recovery, immunoregulation, and emotional processing. Yet, sleep deprivation, chronic sleep restriction, and various types of sleep disorders are all too common in modern society. Failure to meet the recommended 7-9 hours of restful sleep per night is known to increase the risk of several health conditions, reason why regular and adequate sleep should be seen as a priority instead of an unnecessary commodity easily traded as required by the commitments of our busy lives. While both the quantity and the quality of sleep can be largely improved with relatively straightforward practices dictated by good sleep hygiene, emerging research suggests that dietary and supplementation protocols focused on certain foods, nutrients, and biochemical compounds with sleep-promoting properties can act as subsidiary sleep aids in complementing these behavioral changes. The scope of this narrative review is to summarize the available evidence on the potential benefits of selected nutraceuticals in the context of circadian rhythm and sleep disturbances, namely melatonin, magnesium, omega-3 fatty acids, tart cherry juice, kiwifruit, apigenin, valerian root, L-theanine, glycine, ashwagandha, myoinositol, Rhodiola rosea, and phosphatidylserine. A comprehensive recapitulation of the relevant literature is provided, alongside corresponding evidence-based nutritional protocols to promote and improve restful sleep.

Mounting evidence points to the role of semantic knowledge in modulating how we perceive, and subsequently remember, experiences. In healthy aging, prior knowledge becomes increasingly important to guide visual exploration during episodic encoding and retrieval and can hinder performance when incongruous with to-be-learned information. It remains unclear, however, how the dynamic integration of visual information and prior knowledge is altered in neurodegenerative disorders, and whether this impacts oculomotor behaviour. Here, we explored how degradation of the conceptual knowledge base in semantic dementia (SD) impacts the acquisition and retrieval of new information, and how such changes relate to oculomotor behaviour. Ten well-characterised cases of SD were compared to 12 disease-matched cases of Alzheimer's disease (AD) and 24 healthy older Controls. Participants completed a visual search task followed by a surprise memory task where target objects were displayed in either semantically congruent or semantically incongruent locations. Oculomotor performance was evaluated by measuring the time participants spent exploring target congruent areas in each condition. Relative to Controls, visual search and memory performance was significantly compromised in AD, as indexed by slower response times, reduced task accuracy, and more extensive visual exploration directed towards target congruent areas. In contrast, SD patients scored in line with Controls for all behavioural and oculomotor measures on the visual search task when target objects were displayed in semantically incongruent locations. Overall, our findings suggest that degradation of the semantic and episodic memory systems in dementia differentially impacts visual exploration and memory retrieval depending on stimulus congruency.

Background:
Digital fitness applications offer unprecedented access to structured training programs, yet the behavioral factors that predict sustained engagement in real-world settings remain incompletely understood. Methods:
This observational study analyzed data from 522,994 adult digital fitness app users (mean age: 34.2 ± 9.8) of various experience levels followed for six months from their first recorded workout. Long-term adherence was defined as completing at least one workout per week, allowing up to three missed weeks. Adherence trajectories were examined, along with associations between early training behaviors (training frequency, workout duration, exercise composition, equipment diversity), demographic factors, and time to dropout. Effect modifications by sex, workout duration, and training experience were also investigated. Results:
Adherence declined steadily over time, with 18.1% of beginner users remaining adherent at 6 months. The median dropout time was 14 weeks. Higher sustained participation was observed in older versus younger (51+: 23.8%; 18-40: 15%), male versus female (M: 19.9%; F: 15.2%), and more experienced users (intermediate: 28.6%; advanced: 38.2%). Training consistency during the first 28 days was the strongest predictor of adherence and exhibited a protective association that attenuated over time. Greater diversity in equipment use and higher emphasis on resistance exercise were also associated with lower dropout risk. Longer workout duration was associated with improved adherence among users who trained more frequently, particularly early in follow-up. Conclusions:
Early consistency and structured training behaviors were strongly associated with long-term adherence among beginners, with relatively modest differences based on age and sex. These findings suggest that frequent training sessions and engagement with resistance-based exercise during the initial stages of exercise adoption may be relevant behavioral correlates of sustained engagement.